Tiltable crucible or converter for refining pig iron



P. PUXKANDL Aug. 22, 1967 TILTABLE CRUCIBLE OR CONVERTER FOR REEINING PIG IRON 2 Sheets-Sheet 1 Filed Jan. 29, 1964 INVENTOR PEg ER PUXKANDL H IS ATTORNEYS Aug. 22, 1967 3,337,205

TILTABLE CRUCI-BLE OR CONVERTER FOR REFINING PIG IRON P. PUX-KANDL 2 Sheets-Sheet Filed Jan. 29 1954 INVENTOR PETER PUXKANDL H IS ATTORN EYS United States Patent 3,337,205 TILTABLE CRUCIBLE OR CONVERTER FOR REFINING PIG IRON Peter Puxkandl, Linz, Austria, assignor to Vereinigte Osterreichische Eisenund Stahlwerke Aktiengesellschaft, Linz, Austria, a company of Austria Filed Jan. 29, 1964, Ser. No. 340,914 Claims priority, application Austria, Jan. 31, 1963,

3 Claims. (Cl. 266-36) Tiltable crucibles or converters for refining pig iron comprise a refractory-lined cylindrical or pear-shaped vessel, the bottom part of which may be integral with or detachable from the shell part. Mounted to surround such a crucible approximately in the height of the centre of gravity of the charged crucible is a closed or horseshoe-like, open carrying ring which is rigidly connected with two trunnions. The crucible must be tiltable from the substantially vertical blowing position into the upsidedown discharging position and back into the upright position by means of electric or hydraulic drive means acting on the trunnions. The carrying ring has to securely hold the crucible in any position and to transmit the forces exerted by the drive to the crucible.

It is desirable to design the bearing and the guidance of the crucible in such manner that the supporting element which is unstressed in the upright blowing position of the crucible and in its upside-down position, respectively, can expand without friction. This requirement is the more important the larger the crucibles are.

Whereas in the previously known construction, in which the bearing surfaces of the supporting elements and of the carrying body were arranged in vertical relation to the axis of the crucible, a friction less expansion of the respective unstressed bracket or claw was possi ble, the disadvantage arose that the unstressed bracket was lifted somewhat off the bearing surface, due to the longitudinal expansion of the vessel. The clearance depends on the size of the crucible and on the dimension of the carrying body; in the case of large crucibles having large carrying rings, the clearance caused by expansion results in the crucible rocking to and fro during erecting and tilting into the upside-down position, respectively, which may cause a heavy wear of the supporting elements (claws).

It is an object of the invention to avoid these disadvantages and difficulties. The invention resides in that in a tiltable crucible or converter for refining pig iron which is supported by supporting elements taking up hearing stresses, such as pairs of brackets or claws, on a carrying body or ring surrounding the crucible, the bearing surfaces of the supporting elements define inclined planes slanting towards the centre of the ring, The inclination of the bearing surfaces advantageously corresponds to the ratio that the height of the carrying ring bears to the diameter of the vessel. The bearing surfaces may be formed by two pairs of Wedges having a freedom of movement in the longitudinal direction of the crucible, and arranged centrally between the two pairs of wedges there may be a stop, which also allows a free movement in the longitudinal direction of the crucible, but has no freedom of movement in the peripheral direction.

The idea of the invention thus is based on the consideration that the bearing surfaces are given the same inclination as the direction of the thermal expansion of those peripheral points of the crucible shell on which the supporting elements are mounted.

In the drawing an embodiment of the invention is explained more fully. FIG. 1 is a partial vertical sectional view of the crucible, FIG. 2 is a lateral view in the horizontal tilted position, FIG. 3 is a diagrammatic representation of the thermal expansion of the crucible shell relative to a carrying body, and FIG. 4 shows on an enlarged scale a sectional view showing crucible shell, supporting elements and carrying body in the blowing position as viewed along the line IV-IV of FIG. 5. FIG. 5 is a showing of the design of the supporting elements, again in the blowing position.

In FIG. 1 numeral 1 denotes the refractory-lined crucible, Around the shell the carrying ring 2 is arranged, which is box-like or has a C-shaped section. It is rigidly connected with two trunnions (not shown). On the crucible wall 1' pairs of brackets or claws 3, 3 are fixed, e.g. by welding, one pair of claws preferably being arranged in the plane of tilting of the vessel and two further pairs of claws being disposed as supporting elements in a plane perpendicular to the plane of tilting.

In the diagrammatic representation of FIG. 3, letters A and A designate points of the periphery of the crucible shell 1 which, due to thermal expansion, tend to move the distance'a, a to B and B. The position of points B and B, respectively, is dependent on the ratio of h to d and corresponds to the ratio that H (height of the carrying ring) bears to D (diameter of the vessel), because the expansion is a linear function of the temperature and of the dimension of the vessel and of the carrying ring.

According to the proposal of the invention the bearing surfaces of the supporting elements on the carrying body are made with the same inclination as corresponds to the theoretical thermal expansion of the peripheral points A and A. For this purpose, the bearing surfaces of each supporting element are formed by pairs of wedges 4, 4' and 5, 5', respectively. With this inclination of the bearing surfaces it is to be expected that the clearance 6 occurring either in the upright position or in the upside-down position is equally large in any state of expansion. As in the construction according to the invention the clearance 6 does not occur in the longitudinal direction of the vessel by perpendicularly to the inclined planes, the clearance naturally is always the same. With a proper adjustment of the Wedges it can theoretically be almost nil. During tilting, only a slight and hardly noticeable shift of the crucible will be observed, after the friction is overcome.

In the embodiment according to FIGS. 2 and 5 the pairs of wedges 4, 4' and 5, 5, respectively, are arranged in spaced relation, in such manner that each of them will take up half of the bearing pressure P/2. They have a freedom of motion in the peripheral direction of the crucible, as is indicated at X in FIG. 5. Centrally arranged between the two pairs of wedges is a stop 7 which prevents a movement in the peripheral direction of the crucible, but has a freedom of motion y in the longitudinal direction. In the horizontal tilted position of the crucible the stop 7 enables the support of its entire weight P in the vertical direction, whereas it does not hamper the friction-free expansion in the upright blowing position and in the upside-down position.

What I claim is:

1. A tiltable metallurgical vessel comprising a crucible for refining pig iron having pairs of brackets spaced around its periphery and connected to the crucible wall, each bracket having a projecting flange provided with an inclined bearing surface slanting towards the center of the crucible, a carrying ring for supporting said crucible having inclined bearing surfaces on the upper and lower surfaces thereof at points corresponding to the positions of the brackets, said ring bearing surfaces having inclined bearing surfaces slanting towards the center of the ring at angles substantially complemental to the bearing surfaces on brackets, the bearing surfaces on said brackets and the bearing surfaces on said ring facing each other, said bearing surfaces on each pair of said brackets being spaced apart a distance slightly greater than the distance between corresponding bearing surf-aces on said ring to provide a clearance therebetween.

2. The crucible set forth in claim 1 wherein each bracket is provided with two peripherally spaced-apart bearing surfaces engaging with corresponding bearing surfaces on said carrying ring, a stop between said two bearing surfaces on said bracket and a groove on the carrying ring receiving said stop, the bearing surfaces on said brackets and said ring having freedom of movement in the peripheral direction, and said stop having freedom of movement in the longitudinal direction.

3. The crucible set forth in claim 1 in which the inclinations of said bearing surfaces correspond to the ratio of the height of the carrying ring to the diameter of said crucible.

References Cited UNITED STATES PATENTS 3,000,621 9/1961 Puxkandl 266-36 X 3,146,983 9/1964 Johnson 26639 X 3,163,696 12/1964 Johansson et a1. 266-36 3,191,921 6/1965 Johnson 266-36 FOREIGN PATENTS 1,226,126 7/1960 France.

I. SPENCER OVERHOLSER, Primary Examiner.

J. M. ROMANCHIK, E. MAR, Assistant Examiners. 

1. A TILTABLE METALLURGICAL VESSEL COMPRISING A CRUCIBLE FOR REFINING PIG IRON HAVING PAIRS OF BRACKETS SPACED AROUND ITS PERIPHERY AND CONNECTED TO THE CRUCIBLE WALL, EACH BRACKET HAVING A PROJECTING FLANGE PROVIDED WITH AN INCLINED BEARING SURFACE SLANTING TOWARDS THE CENTER OF THE CRUCIBLE, A CARRYING RING FOR SUPPORTING SAID CRUCIBLE HAVING INCLINED BEARING SURFACE ON THE UPPER AND LOWER SURFACES THEREOF AT POINTS CORRESPONDING TO THE POSITIONS OF THE BRACKETS, SAID RING BEARING SURFACES HAVING INCLINED BEARING SURFACES SLANTING TOWARDS THE CENTER OF THE RING AT ANGLES SUBSTANTIALLY COMPLEMENTAL TO THE BEARING SURFACES ON BRACKETS, THE BEARING SURFACES ON SAID BRACKETS AND THE BEARING SURFACES ON SAID RING FACING EACH OTHER, SAID BEARING SURFACES ON EACH PAIR OF SAID BRACKETS BEING SPACED APART A DISTANCE SLIGHTLY GREATER THAN THE DISTANCE BETWEEN CORRESPONDING BEARING SURFACES ON SAID RING TO PROVIDE A CLEARANCE THEREBWTEEN. 